{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,30]],"date-time":"2026-03-30T12:05:03Z","timestamp":1774872303017,"version":"3.50.1"},"reference-count":28,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2018,11,15]],"date-time":"2018-11-15T00:00:00Z","timestamp":1542240000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We evaluate the spectral resolution and the detection thresholds achievable for a photoacoustic spectroscopy (PAS) system in the broadband infrared wavelength region     3270   n m  \u2272 \u03bb \u2272 3530   n m      driven by a continuous wave optical parametric oscillator (OPO) with      P \u00af   \u2248  1.26  W    . The absorption spectra,      I PAS   (  \u03bb i  )     , for diluted propane, ethane and methane test gases at low concentrations (    c \u223c 100   ppm     ) were measured for \u223c1350 discrete wavelengths     \u03bb i    . The      I PAS   (  \u03bb i  )      spectra were then compared to the high resolution cross section data,     \u03c3 FTIR    , obtained by Fourier Transform Infrared Spectroscopy published in the HITRAN database. Deviations of 7.1(6)% for propane, 8.7(11)% for ethane and 15.0(14)% for methane with regard to the average uncertainty between      I PAS   (  \u03bb i  )      and the expected reference values based on     \u03c3 FTIR     were recorded. The characteristic absorption wavelengths     \u03bb res     can be resolved with an average resolution of     \u03b4  \u03bb res  \u223c 0.08   nm     . Detection limits range between     7.1     ppb (ethane) to     13.6     ppb (methane). In an additional step, EUREQA, an artificial intelligence (AI) program, was successfully applied to deconvolute simulated PAS spectra of mixed gas samples at low limits of detection. The results justify a further development of PAS technology to support e.g., biomedical research.<\/jats:p>","DOI":"10.3390\/s18113971","type":"journal-article","created":{"date-parts":[[2018,11,15]],"date-time":"2018-11-15T11:32:47Z","timestamp":1542281567000},"page":"3971","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Quantitative Evaluation of Broadband Photoacoustic Spectroscopy in the Infrared with an Optical Parametric Oscillator"],"prefix":"10.3390","volume":"18","author":[{"given":"Henry","family":"Bruhns","sequence":"first","affiliation":[{"name":"Hochschule f\u00fcr Angewandte Wissenschaften Hamburg, Fakult\u00e4t Technik und Informatik, Department Maschinenbau und Produktion, Berliner Tor 21, 20099 Hamburg, Germany"},{"name":"School of Engineering and Computing, University of the West of Scotland, High Street, Paisley PA1 2BE, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0781-5248","authenticated-orcid":false,"given":"Marcus","family":"Wolff","sequence":"additional","affiliation":[{"name":"Hochschule f\u00fcr Angewandte Wissenschaften Hamburg, Fakult\u00e4t Technik und Informatik, Department Maschinenbau und Produktion, Berliner Tor 21, 20099 Hamburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yannick","family":"Saalberg","sequence":"additional","affiliation":[{"name":"Hochschule f\u00fcr Angewandte Wissenschaften Hamburg, Fakult\u00e4t Technik und Informatik, Department Maschinenbau und Produktion, Berliner Tor 21, 20099 Hamburg, Germany"},{"name":"School of Engineering and Computing, University of the West of Scotland, High Street, Paisley PA1 2BE, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Klaus Michael","family":"Spohr","sequence":"additional","affiliation":[{"name":"School of Engineering and Computing, University of the West of Scotland, High Street, Paisley PA1 2BE, UK"},{"name":"Scottish University Physics Alliance (SUPA), University of Glasgow, University Avenue, Glasgow G12 8QQ, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,11,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1930","DOI":"10.1016\/S0140-6736(98)07552-7","article-title":"Volatile organic compounds in breath as markers of lung cancer: A cross-sectional study","volume":"353","author":"Phillips","year":"1999","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"027108","DOI":"10.1088\/1752-7155\/6\/2\/027108","article-title":"The versatile use of exhaled volatile organic compounds in human health and disease","volume":"6","author":"Boots","year":"2012","journal-title":"J. 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